/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gray-100);
    color: var(--gray-800);
    line-height: 1.5;
    min-height: 100vh;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-lg {
    padding: 16px 32px;
    font-size: 18px;
    border-radius: var(--radius);
}

.btn-icon {
    font-size: 1.2em;
}

/* ==================== LANDING PAGE ==================== */
.landing-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.landing-content {
    flex: 1;
    max-width: 600px;
    margin: 0 auto;
    padding: 40px 20px;
}

.logo-section {
    text-align: center;
    margin-bottom: 40px;
}

.logo-icon {
    font-size: 64px;
    margin-bottom: 16px;
}

.logo-section h1 {
    font-size: 32px;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.tagline {
    font-size: 18px;
    color: var(--gray-500);
}

.features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 40px;
}

.feature-item {
    background: white;
    padding: 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.feature-icon {
    font-size: 28px;
}

.feature-text h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 4px;
}

.feature-text p {
    font-size: 13px;
    color: var(--gray-500);
}

.cta-section {
    text-align: center;
    margin-bottom: 40px;
}

.cta-hint {
    margin-top: 12px;
    font-size: 14px;
    color: var(--gray-500);
}

.instructions {
    background: white;
    padding: 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.instructions h2 {
    font-size: 20px;
    margin-bottom: 16px;
    color: var(--gray-900);
}

.instructions h3 {
    font-size: 16px;
    margin: 20px 0 12px;
    color: var(--gray-800);
}

.instructions ol, .instructions ul {
    padding-left: 24px;
}

.instructions li {
    margin-bottom: 8px;
    color: var(--gray-600);
}

.instructions code {
    background: var(--gray-100);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 14px;
    color: var(--primary);
}

.landing-footer {
    text-align: center;
    padding: 20px;
    color: var(--gray-400);
    font-size: 14px;
}

/* ==================== PROJECT PAGE ==================== */
.app-header {
    background: var(--primary);
    color: white;
    padding: 16px 20px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 12px;
    max-width: 600px;
    margin: 0 auto;
}

.back-btn {
    color: white;
    text-decoration: none;
    font-size: 24px;
    padding: 4px 8px;
}

.header-content h1 {
    flex: 1;
    font-size: 18px;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.currency-badge {
    background: rgba(255,255,255,0.2);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
}

/* Stats */
.stats-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}

.stat-card {
    background: white;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 16px;
}

.stat-card.balance {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    margin-bottom: 16px;
}

.stat-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.stat-icon {
    font-size: 32px;
}

.stat-card.balance .stat-icon {
    font-size: 40px;
}

.stat-info {
    flex: 1;
}

.stat-label {
    display: block;
    font-size: 13px;
    opacity: 0.8;
    margin-bottom: 4px;
}

.stat-value {
    display: block;
    font-size: 20px;
    font-weight: 700;
}

.stat-card.balance .stat-value {
    font-size: 24px;
}

.stat-card.income {
    border-left: 4px solid var(--success);
}

.stat-card.expense {
    border-left: 4px solid var(--danger);
}

/* Transactions List */
.transactions-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    padding-bottom: 100px; /* Space for bottom nav */
}

.transactions-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.transaction-item {
    background: white;
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow);
    display: flex;
    gap: 12px;
}

.tx-icon {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    flex-shrink: 0;
}

.transaction-item.income .tx-icon {
    background: rgba(16, 185, 129, 0.1);
}

.transaction-item.expense .tx-icon {
    background: rgba(239, 68, 68, 0.1);
}

.tx-content {
    flex: 1;
    min-width: 0;
}

.tx-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 8px;
    margin-bottom: 4px;
}

.tx-amount {
    font-size: 16px;
    font-weight: 700;
}

.transaction-item.income .tx-amount {
    color: var(--success);
}

.transaction-item.expense .tx-amount {
    color: var(--danger);
}

.tx-time {
    font-size: 12px;
    color: var(--gray-400);
    white-space: nowrap;
}

.tx-description {
    font-size: 14px;
    color: var(--gray-600);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.tx-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 8px;
    font-size: 12px;
    color: var(--gray-400);
}

.tx-user {
    display: flex;
    align-items: center;
    gap: 4px;
}

.tx-invoice {
    display: flex;
    align-items: center;
    gap: 4px;
    color: var(--primary);
    cursor: pointer;
}

.tx-invoice:hover {
    text-decoration: underline;
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--gray-400);
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray-400);
}

.empty-state .empty-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.8);
}

.modal-content {
    position: relative;
    max-width: 90vw;
    max-height: 90vh;
    z-index: 1;
}

.modal-content img {
    max-width: 100%;
    max-height: 90vh;
    border-radius: var(--radius);
}

.modal-close {
    position: absolute;
    top: -40px;
    right: 0;
    width: 36px;
    height: 36px;
    border: none;
    background: white;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Bot Info */
.bot-info {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    text-align: center;
    font-size: 14px;
    color: var(--gray-400);
}

.bot-info a {
    color: var(--primary);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    display: flex;
    justify-content: center;
    gap: 0;
    padding: 8px 0;
    padding-bottom: max(8px, env(safe-area-inset-bottom));
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    z-index: 100;
}

.nav-btn {
    flex: 1;
    max-width: 120px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 8px 16px;
    border: none;
    background: transparent;
    cursor: pointer;
    transition: all 0.2s;
    border-radius: var(--radius-sm);
    margin: 0 4px;
}

.nav-btn:hover {
    background: var(--gray-100);
}

.nav-btn.active {
    background: var(--primary);
    color: white;
}

.nav-icon {
    font-size: 20px;
}

.nav-label {
    font-size: 12px;
    font-weight: 600;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 16px;
    padding: 20px 0;
    margin-top: 12px;
}

.page-btn {
    width: 40px;
    height: 40px;
    border: none;
    background: white;
    border-radius: 50%;
    font-size: 20px;
    font-weight: 600;
    color: var(--gray-600);
    cursor: pointer;
    box-shadow: var(--shadow);
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.page-btn:hover:not(:disabled) {
    background: var(--primary);
    color: white;
}

.page-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.page-info {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-600);
    min-width: 60px;
    text-align: center;
}

/* ==================== 404 PAGE ==================== */
.error-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.error-content {
    text-align: center;
}

.error-icon {
    font-size: 80px;
    margin-bottom: 20px;
}

.error-content h1 {
    font-size: 72px;
    color: var(--gray-300);
    margin-bottom: 16px;
}

.error-content p {
    font-size: 18px;
    color: var(--gray-500);
    margin-bottom: 24px;
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 480px) {
    .features {
        grid-template-columns: 1fr;
    }

    .stat-card.balance .stat-value {
        font-size: 20px;
    }

    .stat-value {
        font-size: 16px;
    }

    .stat-row {
        grid-template-columns: 1fr;
    }
}